Graugés Pous, EugeniBABAR Collaboration2020-10-072020-10-072019-02-220031-9007https://hdl.handle.net/2445/171018Recent investigations have suggested that the six-quark combination u u d d s s could be a deeply bound state ( S ) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in Υ → S ¯ Λ ¯ Λ decays based on a sample of 90 × 1 0 6 Υ ( 2 S ) and 110 × 1 0 6 Υ ( 3 S ) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined Υ ( 2 S , 3 S ) → S ¯ Λ ¯ Λ branching fraction in the range ( 1.2 - 1.4 ) × 1 0 − 7 are derived for m S < 2.05     GeV . These bounds set stringent limits on the existence of such exotic particles.7 p.application/pdfengcc- by (c) Graugés et. al. , 2019http://creativecommons.org/licenses/by/3.0/es/QuarksMatèria fosca (Astronomia)Partícules (Matèria)QuarksDark matter (Astronomy)Particlesinfo:eu-repo/semantics/article6945052020-10-07info:eu-repo/semantics/openAccess